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U.S. DEPART MBWP^P F AGRICULTURE
BUREAU OF BHT0M0L0O1 CIRCULAR No. 166.
L. O. HOWARD. I ntomolosisl anil ( lurl ,.( Iiuir»u.
FLOUR PASTE IS \ CONTROL FOR RED SPIDERS
AS \ SPREADER FOR CONTACT INSECTICIDES.
WILLIAM B. PARKER
BUREAU OF EXTOMOLOGY.
L. O. Howard. Entomologist and Chief of Hunan.
C. L. Mari.att. Entomologist and Acting Chief in Absence of Chief.
R. S. Clifton. Executive Issistant.
W. F. Tastet. Chief Clerk.
F. H. Chittenden, in charge of truckorop and stored product insect investigations,
A. D. Hopkins, in charge of forest insect investigations.
W. D. HtrNTEB, in charge of southern field crop insect investigations.
F. M. Webster, in charge of cereal and forage insect investigations.
A. L. Quaintance. in charge of deciduous fruit insect investigations.
E. F. Phillips, in charge of bee culture.
I). M. Rogers, in charge of preventing spread of moths, petit work.
Rolla P. Cubbie, in charge of editorial work.
Mabel Colcord. in charge of library.
Truck Crop and Stored Product Insect Investigations.
F. H. Chittenden, in charge.
C. H. Popenoe, William P». Parker. H. O. Marsh. M. M. High, Fred A. John-
ston, John E. Graf. C. F. Stahl, D. E. Fink, entomological assistants.
A. B. Duckett, scientific assistant.
I. J. Condit, collaborator in California.
W. N. Ord, collaborator in Oregon.
Thomas H. Jones, collaborator in Porto Rico.
Marion T. Van Horn. Pauline M. Johnson. Anita M. P.allinger. preparators,
United States Department of Agriculture,
BUREAU OK ENTOMOLOGY.
L. O. IIOWAKD. Bntomolc i»l ."■! Chief of Uuir
FLOUR PASTE As A CONTROL FOB RED SPIDERS \\l>
As A SPREADEB FOB CONTACT [NSECTICIDE8.
Bj H ill hm I'. I'm:
Entomali >•!• til i -.-i^in ill .
1:1 -i i h i 'i i \ri i;i mi STS.
I > 1 1 1 ■ 1 1 1 i_r some spraj ing experiments for the control i f the red spider
(Tetranychws bimacvlatus Harv.) on hops in L912 some difficulty was
F *^ ' VI
Ki'.. 1 .—Lime •sulphur mixture and Door paste ii.fr half), Bhowii -
flour paste; lime-sulphur mixture straight (right balf), Bhowing due to
lack of Dour paste (Original.)
experienced in obtaining an effective spreader for the lime-sulphur
solutions, due to the fact that soap forms a precipitate with the cal-
cium polysulphid. While testing the following combination — flow-
2 I I. oil; PASTE AS A CONTROL FOR RED SPIDERS.
crs of sulphur 15 pounds, water LOO gallons, and Hour paste (as a
"sticker") 4 gallons — a formula advised for red spiders in Bulletin
NO. 154 by Mr. W. II. Voids of the California Experiment Station,
it was observed that the mixture spread over the leaves very readily.
The Hour paste was evidently the spreader and was accordingly
mixed with the lime-sulphur solutions. The result was a smooth
mixture which spread over the foliage very readily and gave unusual
results as an arachnicide. The proper proportions were found to be
4 gallons of paste (4 pounds of Hour) to 100 gallons of spray. Table
I graphically represents the relative effectiveness of the lime-sulphur
spray, with and without the flour paste, for the red spider on hops.
Table I. — Relative effectiveness of lime-sulphur spray, with and without flow
paste, against the red spider, on hops in the Sacramento Valley of California,
of mites of mites
Lime-sulphur, 36° Baumi'>, 1-75; flour paste, 4-100.
Lime-sulphur, 36° Baume, 1-75
From the foregoing table it is very evident that the use of flour
paste greatly increases the efficiency of the lime-sulphur spray and
that without the paste the spray was very ineffective. These results
were substantiated by other experiments and. by a check experiment
with the flour paste. 4-100. used without the lime-sulphur, it was
found that the increased efficiency was mainly due to the spreading
effect of the paste.
Having proved a most efficient, cheap, and convenient spreader for
the lime-sulphur solutions, some experiments were conducted with
flour paste in combination with nicotine sulphate upon the hop aphis
(Phorodon humuli Schrank). (See Table II.)
Table II. — Results obtained by spraying with combinations of flour paste and
nicotine sulphate in different proportions against the hop aphis, Sacramento
Valley of California. 1912.
Nicol ine sulphate. 1-2.000: flour paste, 4-100 027
Nicotine sulphate, 1-2.500; flour paste. 4-100 611
Nicotine sulphate. 1 3.000; flour paste, 4-100
Nicotine sulphate. 1 3,000; flour paste, 4-100 148
From the preceding table it is very evident that Hour paste, 4-100,
is a very effective spreader for nicotine sulphate.
The efficiency of Hour paste as a spreader was very evident to the
writer, but it was deemed advisable thorough!}' to illustrate this point.
I'l OUR PASTI VS \ i u\ i Ri »i i OH RED SI'IDKRS.
Two hopvines were accordingly sprayed, one with lime-sulphur
straight nnd the other with lime-sulphur and flour paste, t-100.
The relative spreading effecl of these two sprays i- shown in tiu
ore l. The left half of the figure represents the lime-sulphur and
the flour paste in combination, while tin' right half represents the
lime-sulphur straight. The spotted effect produced l>y the lime-
Bulphur mixture alone is in strong contrast i<> the even appearance
of the other half of i In* illustration.
During some spraying experiments with nicotine sulphate and
flour paste upon the hop aphis it was observed thai many <>f the
smaller aphides had become pasted onto the leaves. From this data
it was assumed that ;i stronger solution of paste would be effective
against the more delicate aphides and mites, and the following
experiments were conducted upon the red spider.
Tabu III. Results of i rperimentt with flour past* ipraycd againti tin red
tpider "» ho/is in /in sni niiiii nin I nth a ni California, 1912.
Flour paste, 8 100.
Jul v 13
17 . r,
Flour pasio. 10 1 ■ m >
These experiments prove that Hour paste, 8 LOO and 10-100. is
effective against Tetrany chits bimaeulatus. The paste has no effect
upon the i'ir.i. r >. however, and in controlling the mites a second
application 7 to 1<> days after the firsl is necessary to catch the mites
that emerge from the eggs,
A few preliminary experiments were conducted with this material
upon Tetranychus mytilaspidis Riley which was attacking pears, with
verj encouraging results, and it is very probable that flour paste,
8-100, will give good results when applied for any of the small leaf-
The last of June, 1912, flour paste, s 100, was applied for the hop
aphis (then in the younger stages) with a 97 per cent efficiency.
These were encouraging results, bul later experiment- proved that.
'in moderate weather allow 10 days and In bot weather 7 days between
-i FLOUR PASTE AS A CONTROL EOR RED SPIDERS.
although the solution was effective against some very delicate species
and the younger stages of the hop aphis, it was not effective against
the stouter aphides.
When the paste was dry the mites and more delicate aphides
treated were found firmly pasted onto the leaves. Later the paste
film was observed to crack and partially scale off. leaving the leaf
free to perform its natural functions.
The neutrality of this spray was proved by the fact that when
applied upon the foliage and blossoms of the hop in proportions as
high as 12 pounds to 100 gallons no injurious effect resulted.
"W hen sprayed onto the burrs and delicate hop cones it did not pre-
vent pollination or injure the appearance of the scales.
Flour paste has proved effective when applied for red spiders upon
the following plants:
Chrysanthemum (may spot leaves
used too near blossoming time).
Cucumber, greenhouse and field.
Poses in field.
Violets, field and greenhouse.
The Hour paste was not satisfactory when used for the red spider
on greenhouse roses (did not spread well), greenhouse carnations, or
field sweet peas.
PREPARATION OF PASTE.
To prepare the flour paste, mix a cheap grade of wheat flour with
cold water, making a thin batter, without lumps: or wash the flour
through a wire screen with a stream of cold water. Dilute until there
is 1 pound of flour in each gallon of mixture. Cook until a paste is
formed, stirring constantly to prevent caking or burning. Add suffi-
cient water to make up for evaporation.
Flour paste may also be prepared by stirring boiling water into
a moderately thin batter until there is 1 pound of flour in each
gallon of mixture and allowing it to stand until the starch is all
If the paste is not sufficiently cooked, the resulting spray will not
be effective, and if overcooked the paste will harden when thor-
oughly cool, and will not mix with water very readily. Usually,
however, the paste is used as it is prepared, and overcooking is not
When mixed in the spray tank flour paste has a tendency to settle,
and in order to do satisfactory work agitation is necessary. This
is but a slight disadvantage, and is necessary with most materials.
Flour paste appears to be a very effective spreader for lime-sul-
phur and nicotine-sulphate sprays. Cheap flour can be purchased
I I 111 i; PASTE \- \ CONTROI POB BED SPIDI RS. D
for less 1 1 1 ;i n half the cost of whale-oil Boap. It is always obtain
able, and having i dor it i- less offensive to use than the whale
oil and fish-oil -<>;i|i~. Winn used alone it ili<- rate of v gallons i v
|)(iiiinl- flour) to 100 gallons of water it is effective against several
leaf feeding mites and some verj delicate aphides. The possibility
Fig. 2. — Hindu making Dour paste, Sacramento Valley, Cal., 1 ; • 1 - . (Original.)
of it- use as a spreader for lime-sulphur sprays for scale insects and
fungi and a> a "sticker" for arse nicals has not yet been worked out,
but from observations during the past four months it is believed tbat
it may have some value along these lines.
§ of A <n '" ultui < .
Washington, I >. C, November .'■>'. 1912.
ADMTIOXAL COPIES ofi!i< pob)
xi • procured from the BuPKRiNTBfD-
ent of' Documents, Government Printing
Oii'.ce, Washington . I> . < r oopy
UNIVERSITY OF FLORIDA
3 1262 09216 5777